Despite its relatively small territory, the Republic of Armenia is distinguished by an exceptionally rich diversity of plant species and plant communities. This richness is the result of the complex geological structure of the Earth’s crust, the great variability of climatic and soil conditions, the strongly dissected relief, and—most importantly—the country’s geographically favorable position from a florogenetic perspective. Several major botanical regions intersect within the territory of the republic, namely the Caucasian, Iranian, and Eastern Mediterranean regions.
The extensive Caucasian botanical region (province) is characterized by the predominance of mesophilous vegetation types, including forests and meadows. The Armenian–Iranian region (province) is dominated by xerophilous species forming semi-desert, phryganoid, and arboreal vegetation, as well as tragacanth steppes. Arboreal vegetation in this region is represented mainly by sparse xerophilous forests, and even alpine vegetation has undergone processes of aridization. The influence of the Eastern Mediterranean botanical region is particularly pronounced in the western parts of the republic, especially within the territories of the Shirak and Aragatsotn marzes.
The flora of the republic includes approximately 3,600 species of vascular plants (about 60% of the flora of the Caucasus), belonging to more than 800 genera and 160 families. The boundaries of the distribution ranges of many plant species pass through the territory of Armenia. The most species-rich plant families include Asteraceae (429 species), Fabaceae (346), Poaceae (336), Rosaceae (210), Brassicaceae (203), Caryophyllaceae (183), Lamiaceae (153), Apiaceae (Umbelliferae) with 132 species, and others, which together account for more than 55% of the total species composition of the flora.
A total of 123 plant species in Armenia are endemic. The endemic taxa of the republic’s flora comprise 26 families, 56 genera, and 124 species. Among the genera, Pyrus (pear) ranks first: 32 species occur within the republic, of which 12 are endemic, and 6 are confined exclusively to the floristic regions of Vayots Dzor, Zangezur, and Meghri. The second position is occupied by the genus Centaurea, within which intensive processes of speciation are also observed. Similar patterns are characteristic of the genera Cousinia and Astragalus.
Endemic species include the Nairian almond, the Armenian pear, Takhtajan’s spurge, Tamamshyan’s onion, Makalyan’s stelleropsis, Tiolran’s thyme, the Ararat ishomarola, Barsaghyan’s flax, and others. A special place is occupied by wild endemic cereal crops, such as wheat, barley, rye, and oats. According to the Russian botanist N. I. Vavilov, Armenia is one of the ancient centers of origin of spike-bearing cereal crops in Western Asia.
Relict species also occupy a significant place in the flora of the republic; most of them are represented by trees and shrubs, including jujube, yew, plane tree, bear hazel, frankincense, juniper, daphne, myrtle, parilla, and common ivy. Relict herbaceous plants are also present, such as duckweed, white and yellow water lilies, subalpine tall-herb communities, and ferns.
Territorial differences in the species composition of vegetation correspond to the altitudinal zonation of climate and soils. Lowland areas are covered by desert and semi-desert vegetation, whereas high-altitude regions are occupied by alpine vegetation. The forest fund of the republic amounts to 459,900 hectares, of which 334,100 hectares, or 11.2% of the total territory of Armenia, are covered by forests.
